Seals have been used to isolate fluids at various pressures and temperatures. Such seals have existed for use in packing rings, seal rings, piston rings, and gland structures in industrial equipment, such as cylinders, pumps, hydraulics and valves, and in oil field equipment, such as down hole tools and surface equipment, requiring seals, for example, against high pressure and low pressure liquids and gases. Typically, these seals are annular seals.
However, such seals may be eroded or destroyed for machinery and equipment wherein sealing needs to be established at the most severe sealing environments, which includes seal gland design, pressure, fluid media and temperatures. Such seals, whether the dynamic or static type, are usually made, or have portions made, of materials which, to some extent, are resilient or at least are formable. In order to seal effectively, it is usually necessary that the sealing device be placed under some compressive loading between the components of the assembly to be sealed. Because of the compressing load, there is a tendency for portions of formable seals to be subjected to extrusion forces which will either distort the seal and impair its effectiveness as a seal or, in more severe cases, force portions of the seal into clearances between components to be sealed.
In an attempt to overcome this extrusion problem, workers in the field have resorted to various techniques. One common practice employed to prevent such extrusion is the use of a back-up ring of knitted mesh as shown in U.S. Pat. No. 4,219,204. Additionally, seals having the seal lip configuration with an insert are also known in the art and manufactured by Parker Seal Company under the name "Polypac Seal". A widely used seal is the Chevron or vee ring seals. This type of seal is a general shape well known in the art. The material from which it is made is typically resilient, impermeable and homogeneous. For current use of seals of this sort used, see U.S. Pat. No. 4,234,197, entitled Conduit Sealing Systems, issued to A. Amancharla, et al.
It is the object of the current invention to avoid the distortions and other problems of the prior art through the use of a non-homogeneous vee ring seal.